<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <h3>利用jsonp解决跨域问题</h3>
    <button id="btn">按钮</button>
    <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.0/jquery.js"></script>
    <script>
     btn.onclick=function() {

      const xhr = new XMLHttpRequest()
     xhr.open('get','http://localhost:3000/jqueryJsonp')
     xhr.send()
     xhr.onload=function() {
       console.log(xhr.responseText);
       const obj = JSON.parse(xhr.responseText)
       console.log(obj);
     }
     }
    </script>
  </body>
</html>
